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  <td><br><h2>Attribute types - reference</h2></td>
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.TH Attribute_types_-_reference PL "18-JUN-2001   PL www.sgpr.net"

.SH DESCRIPTION
Many of the various attributes are of
standard types.  These types are described here, for reference.

.ig >>
<a name=positionunits></a>
.>>
.SH POSITION UNITS
\fBAbsolute\fR space is measured in inches (or centimeters if
set in the config file).  Origin is always the \fBlower-left\fR
corner of the page/drawing area.
.LP
\fBScaled\fR space is measured in whatever units have been
defined with a \fBproc areadef\fR.
.LP
For more information, see
.ig >>
<a href="scaleunits.html">
.>>
scaleunits
.ig >>
</a>
.>>

.ig >>
<a name=charactersandtext></a>
.>>
.SH CHARACTERS AND TEXT
Any available PostScript font may used when rendering in PostScript; 
otherwise a single standard font is used.  See
.ig >>
<a href="textdetails.html">
.>>
textdetails
.ig >>
</a>
.>>
 for more information about rendering text.
.LP
Text specifications may include embedded 
special characters, which will be rendered in PostScript mode only.
The notation for these is borrowed from unix troff (e.g. \fC\\(bu\fR for 
bullet).  See 
.ig >>
<a href="specialchars.html">
.>>
\fIspecialchars\fR
.ig >>
</a>
.>>

.SH ATTRIBUTE TYPES
The attribute types, listed from simplest to most complex, are:


.LP
.ig >>
<a name=n></a>
.>>
.LP
\fBn\fR
.IP
A single number.  
May be floating point or integer.  
.br
Example: \fCOffset: 3.2\fR

.LP
.ig >>
<a name=dfield></a>
.>>
.LP
\fBdfield\fR
.IP
A reference to a field in the plot data.
Plot data must have already been read using \fBproc getdata\fR.
A \fBdfield\fR may be an integer (\fB1\fR or greater), e.g.
\fC1\fR would refer to the first data field.
If field names have been defined in \fBproc getdata\fR,
\fBdfield\fR may also be one of the defined names.

.LP
.ig >>
<a name=plotvalue></a>
.>>
.LP
\fBplotvalue\fR
.IP
A plottable value given the scaling and ranges that have been
set up with the most recent \fBproc areadef\fR.
See the above description of 
.ig >>
<a href="#positionunits">
.>>
position units
.ig >>
</a>
.>>

.LP
.ig >>
<a name=locvalue></a>
.>>
.LP
\fBlocvalue\fR
.IP
A number or value that 
describes a location or length.
May be either absolute units or scaled units.
.IP
If a suffix of \fC(s)\fR is attached to the end 
of the number, the number is taken as being in scaled 
space, and must be a plottable value (a number for numeric scaling,
a date where date scaling is being used, etc.)
.IP
If the number does not have a (s) suffix, it is interpreted as 
being in absolute space.  
.IP
Special operators: \fCmin\fR may be used to indicate the
minima of a defined plot area, and \fCmax\fR to indicate the maxima.
.IP
Offsets: A +/- offset may be given after the value
(no embedded spaces allowed).  The offset is always an
absolute value.  
Note that it is impossible to specify a negative offset when using date scaling
with a date notation that uses embedded dashes such as mm-dd-yyyy.
See the examples below.
.IP
See the above description of 
.ig >>
<a href="#positionunits">
.>>
position units
.ig >>
</a>
.>>
.IP
Example: \fC3.5\fR = 3.5 absolute units (inches or centimeters).
.br
Example: \fC142(s)\fR = 142 in scaled units (whatever was defined in the
most recent areadef).
.br
Example: \fCmin\fR = the plot area minima
.br
Example: \fCmin-0.1\fR = 0.1 inch below plot area minima
.br
Example: \fC23jan98(s)+0.5\fR = 0.5 inch above the point where 23jan98 (in scaled units) would lie

.LP
.ig >>
<a name=lenvalue></a>
.>>
.LP
\fBlenvalue\fR
.IP
Uses same notation as \fBlocvalue\fR except that it 
describes a distance rather than a location.  
Distances may be given in absolute units or scaled "basic" units
(e.g. for date and datetime this should be a value in days; 
for time scaling this should be a value in minutes).
See the above description of 
.ig >>
<a href="#locvalue">
.>>
locvalue
.ig >>
</a>
.>>

.LP
.ig >>
<a name=xy></a>
.>>
.LP
\fBx y\fR
.IP
A coordinate pair.  Both \fIx\fR and \fIy\fR are \fBlocvalues\fR.
See the above description of 
.ig >>
<a href="#locvalue">
.>>
locvalue
.ig >>
</a>
.>>
.br
Example: \fCLocation: 5.3 1\fR


.LP
.ig >>
<a name=printfspec></a>
.>>
.LP
\fBprintf-spec\fR
.IP
A format specifier as used in the "C" programming language,
used to specify decimal number format.  For example, a printf-spec of
\fC%3.0f\fR rounds to produce numbers like this: 7, 55, 240, 8492.
A printf-spec of \fC%5.2\fR rounds to produce numbers like this: 7.00 55.05 
239.62 8491.50.  
.IP
Another example: \fC$%.2f\fR would yield \fC$82.54\fR
.br
Another example: \fC$%6.2f\fR would yield \fC$ 82.54\fR
.br
Another example: \fC%3.0f%%\fR would yield \fC44%\fR
.br
\fC%g\fR may be used to give the shortest possible representation.

.LP
.ig >>
<a name=string></a>
.>>
.LP
\fBstring\fR
.IP
A character string value containing no embedded white space.  All
white space before and after the string is discarded.  

.LP
.ig >>
<a name=text></a>
.>>
.LP
\fBtext\fR
.IP
A character string value that may contain embedded white space.
The specification may not occupy more than one line, however embedded 
newlines (specified as \fC\\n\fR) may be used to indicate that output should
have multiple lines.
.br
Example:
\fCYaxis.label: Number of Attempts\\nBefore Success\fR

.LP
.ig >>
<a name=multiline></a>
.>>
.LP
\fBmultilinetext\fR
.IP
Text that may be specified using one or more lines.
The last line of the text is indicated by a blank (zero-length) line.
(\fBA common error is to forget to leave a blank line and hence
get incorrect results.\fR)
The maximum number of lines / characters in a multilinetext item
varies, but is generally high enough to be rarely encountered.
Blank lines that are to be part of the text may be escaped 
using a backslash (\\), or by putting some blanks into the line.
.br
.nf
.ft C
Title: Comparison of Survey Techniques 
     By Region 
     \\
     Fall, 1997
.fi
.ft R
.IP
It is also ok to leave the first line blank as in the following 
example:
.nf
.ft C
Title: 
Comparison of Survey Techniques 
By Region 
\\
Fall, 1997
.fi
.ft R


.SH RELATED TO GRAPHICS RENDERING
.LP
\fBpointsize\fR
.IP
An integer point size (usable range is 5 - 30 or so).

.LP
\fBfont\fR
.IP
A postscript font name.

.LP
\fBcolor\fR see 
.ig >>
<a href="color.html">
.>>
color
.ig >>
</a>
.>>

.LP
\fBtextdetails\fR see 
.ig >>
<a href="textdetails.html">
.>>
textdetails
.ig >>
</a>
.>>

.LP
\fBlinedetails\fR see 
.ig >>
<a href="linedetails.html">
.>>
linedetails
.ig >>
</a>
.>>

.LP
\fBsymboldetails\fR see 
.ig >>
<a href="symboldetails.html">
.>>
symboldetails
.ig >>
</a>
.>>

.LP
\fBconditional expression\fR see 
.ig >>
<a href="condex.html">
.>>
condex
.ig >>
</a>
.>>

.ig >>
<br>
<br>
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<a href="Copyright.html">Copyright Steve Grubb</a>
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.>>
